At around 1 p.m. yesterday a group of English football supporters were marching purposefully across Place Charles II, the handsome 17th century square in the centre of Charleroi. The England fans appeared to be strolling along, minding their own business.

All of a sudden, they stopped walking and turned round to face somebody behind them. Oh dear, trouble already? No. The man was a TV producer and the fans' purposeful walk across the square had been for the benefit of his TV crew. They had strolled past the camera and then stopped when he yelled "Cut!" or words to that effect.

Even as this scene was being enacted, three other TV crews were dotted around the small square, all no doubt involved - as indeed was your correspondent - in gathering material for a scene-setter for tonight's anxiously awaited Euro 2000 match between England and Germany.

Interesting though the match undoubtedly is, it is the grim prospect of fan violence, both German and English, that has attracted the TV crews.

Yesterday, however, it was a case of all quiet on the Charleroi front. There were possibly more reporters than fans in this pleasant town just south of Brussels. Walking around the handsome centre with its narrow cobblestone streets and flagstone pavements, one came across small numbers of English fans, usually more concerned with shopping than with causing trouble.

At one point, the unmistakable sound of a choir singing the hymn Abide With Me - sung every year at the FA Cup Final - came ringing across the air. Could this be a new hooligan's eve-of-battle cry? No, it was the man from the Daily Express, complete with his van selling England shirts for the not-so-knockdown price of 500 Belgian francs (about £10).

Everything was quiet yesterday, as it was earlier this week before and after England's game against Portugal in Eindhoven. In theory, things are looking good. The atmosphere, not just in Charleroi, but at all of the Euro 2000 venues and matches so far, has been festive and joyous.

So why all the concern about what could happen today? The answer is threefold. First, the game involves two sets of fans whose most recent violent track record both at the France 98 World Cup and at recent European club games bodes ill.

Second, the Stade du Pays de Charleroi stadium has a maximum capacity of 30,000, which means that as many as 10,000 fans could be ticketless, left to watch the game in bars, cafes and on giant screens. Third - and this is arguably the most worrying consideration - bars and cafes will be open all day, selling alcohol for up to 12 hours before the game, which is due to kick off at 20.45 p.m.

For weeks, Belgian police and security spokesmen have been assuring us that everything is under control, that their 2,500-strong force in Charleroi is ready for every eventuality.

Yesterday, Dominique Colin, a spokeswoman for Charleroi City Council, told The Irish Times that local people were now less worried than two or three months ago. "People were very worried because of everything they read in the press, but then we had a game earlier this week between Yugoslavia and Slovenia and that passed off without any serious incident . . ."

True enough, but Yugoslav and Slovene supporters are not quite the same as England's. The police and city authorities believe that a series of measures, including a security cordon around the ground, the selling of drink in plastic containers and the removal of wooden tables and chairs from cafe streetfronts, will help to defuse the situation by restricting the movement of fans while at the same time denying fans potential "weapons" such as beer glasses, bottles, chairs and tables.

Nathan Rozenberg, president of the Charleroi Retailers' Association, takes a similarly optimistic view, pointing out that nearly all those shopkeepers and bar-owners who had originally threatened to close will be open today, in order to help create an "animated atmosphere". He could be all too right, unfortunately.

He admits there could be trouble, but he hopes it will be avoided, saying: "As for the fact that bars will sell beer, even our strong Belgian beer . . . well, if somebody is bad he does not need beer to behave badly . . . We are preparing as if we might have to go to war but I hope that nothing will happen . . ."

That is what we all hope.